Washington, 19 October (Argus) — The District of Columbia wants to install solar generation at a wastewater treatment plant as part of a deal to clear the way for Exelon to buy local utility Pepco.

The city wants half of the 10MW Exelon has agreed to build in the district located at the Blue Plains treatment plant, with the remaining 5MW spread among community, microgrid and other projects.

"We would like to put more renewable energy on our sewage-treatment plant so that we can eventually island it," District Department of Energy and Environment director Tommy Wells told Argus on the sidelines of the Renewable Energy Markets 2015 conference held in Crystal City, Virginia. Islanding the plant means it has the resources to operate in the event of a wider power outage.

The Blue Plains advanced wastewater treatment plant, located in the southern part of the district, produces 10MW of renewable energy from anaerobic digestion.

Exelon and Pepco Holdings have agreed to develop 10MW of solar in the city as part of a deal to win approval of their merger from district regulators, who initially rejected the deal in August. The city wants 5MW of the new capacity at Blue Plains, but may add more if that capacity is among the 10MW the utilities build, Well said. The plant's site can fit a total of 10MW of solar, Wells said.

Wells said he is still negotiating the projects but hopes to have more information within the next six to eight months.

Exelon and Pepco also agreed to buy 100MW of wind power each year as part of the deal.

The companies filed the updated agreement with the district Public Service Commission on 6 October, but the agency has yet to make a decision.

In addition, Exelon and Pepco would allot a total of $17mn for sustainability, including $3.5mn for a fund to support to support solar development in the district. Another $3.5mn would fund residential and commercial energy efficiency and renewable projects. Exelon would provide $10mn to the district's Green Building Fund to expand the use of clean energy and clean water.